1. Field of the Invention
The invention relates to a distributed network system for connecting a broad variety of electronic devices in a house with a common network.
2. Description of the Related Art
In modern multi-media networks for homes, several devices are connected together. Such devices can be complex multimedia devices like TV sets or DVD players. They can also be less complex devices like temperature controllers, or even very simple devices like jalousie actuators or light switches. All these devices are connected together via a common network.
A common standard for multi-media networks is the HAVI Standard. A home network based on this Standard is disclosed in EP 1044536. This Standard describes different nodes with different capabilities, from simple “base nodes” to complex “full nodes.” A disadvantage is that even the relatively simple “base nodes” require complex and expensive interface hardware for communicating with other nodes. Furthermore, there is no satisfactory mechanism for resolution of resource conflicts as described in the following scenario: a first home inhabitant is listening to music in the bathroom, in the kitchen is another person who uses the intercom to call the bathroom, during this conversation a phone call arrives. There are now three applications: music, intercom, and phone which require access to loudspeakers in the bathroom. Now the applications affect each other—the music application is affected by the intercom application, and both are affected by the phone application.
The resource conflict can be resolved only by a “full AV node” which can act as a master controller, e.g. a central resource manager. Therefore a very complex central controller is required.
In the example of a home, we may expect the intercom to be from a different manufacturer than the DVD player. Furthermore, the DVD player may have been added to the network at a later time after installation of the network. This leads to the problem of how the applications can interact with each other in a sensible way, when they were unknown to each other at construction time. A solution provided in EP 1044536 uses an intelligent update method for updating the system by retrieving updated software. Often an import of software cannot be accepted for reliability and stability reasons, or simply because some devices are not updateable. Furthermore, an intelligent updating mechanism requires at least one complex “full node.”